Here is the problem: you have a document where all pages are in Portrait mode, but you need to insert a page in Landscape mode. To do this, you must create a page style with landscape page orientation:

In the Stylist, click on the Page Style button, right-click in the window, and choose New.

In the Page Style dialog box, click on the Page tab.

Under Orientation, click on the Landscape radio button.

Specify other settings and press OK.

To insert a landscape-oriented page:

Choose Insert -> Manual Break.

Click on the Page break radio button.

Select the newly created landscape page style from the Style drop-down menu.

To get back to the portrait mode repeat the procedure, but in step 3 select the portrait page style.

Bhikkhu Pesala wrote:You can set an automatic Next Style for following page in the page style organizer tab then you don't need a second manual page break. In most cases, users want to insert a single landscape page for a spreadsheet.

I have left and right page styles set up in landscape orientation and use Next Style to alternate left and right. To return to portrait orientation, I use the manual break.

Bhikkhu Pesala wrote:What's the best way to add a header or footer with page numbers to a landscape page?

The best way to add a header or footer on a landscape page is a bit of a kludge, but we can take a little satisfaction in the fact that Word requires the same kludge so it's more than an OOo problem. It's the method documented in the Writer Guide, chapter 4 (Formatting Pages) under subsection "Creating Headers and Footers" in the topic "Portrait Headers on Landscape Pages."

The basic method uses a frame for the header and one for the footer, rotated so that they align with the "portrait" edges.

1. Look at the portrait page style settings to figure out how much room you'll need for header, footer, and left and right margins (if those are different, such as for a book layout), then set up your landscape pages style(s) to match. Keep in mind there's a "spacing to content" setting on the portrait header and footer that you'll have to include in the landscape margin. Also keep in mind there's usually a wider margin for the binding edge ("inside" margin).

2. In a blank paragraph on the landscape page, type the footer text and insert fields to match the existing footer. Apply the Footer paragraph style so it matches the portrait footers (including tabs, font, etc.).

3. Select the text and choose Format> Character. On the Position tab, set the rotation to 270 degrees and click OK.

4. With the text still selected, choose Insert> Frame. On the Type tab, set the position of the frame to match the portrait footer position.

5. Repeat steps 2-4 for headers.

6. Perform steps 1-5 for "left" and "right" landscape page styles.

If your header or footer are formatted in tables, use this procedure:

A. Insert a frame into the landscape page. Choose "Automatic" width on the Type tab (first tab) and click OK to close the frame editor.

B. With the frame still selected, press Enter. This puts the frame into edit mode, ready for the next step.

C. Go to a portrait page. If you have different left and right page styles, of course, you'd want to go to whichever style you need. Select the footer (or header) table and copy. Paste into the landscape page's frame. Because the frame width is automatic, the frame should resize to the correct width of the footer (or header).

D. Rotate the frame. To do this, double-click on the frame border to take it out of edit mode and open the frame properties. On the Options tab, at the bottom of the dialog in the Text Direction drop-down list, choose "right-to-left (vertical)". (NB: I haven't figured out why yet, but sometimes the frame retains its width and resizes its height to fit the table, so I have to drag the frame border to narrow it down to the correct size. Other times, the frame resizes correctly and no adjustments are needed.) I'm not sure how these instructions should change for languages that are not read left-to-right.